Instrument casing



A May 25, 1943. J. A. CALDWELL 2,319,845

` INSTRUMENT cAsING l f Filed'Jan. 15.1941A FIG] 4\ l 6 s? 28 f i Y WVM 8 nwENron J HNACALUWELL BY W v oRNeY Patented May 25, 1943 INSTRUMENT CASING .mm A. calaweu, Philadelphia. Pa., signor to The Brown Instrument Company, Philadelphia, Pa., a corporation of Pennsylvania Application January 15, 1941, Serial No. 374,467

7 Claims.

The present invention relates to instrument casings and more particularly to an instrument casing which is adapted to be made of several parts that are fastened together in a manner to give the appearance of .being a single structural member. p

Quite often in the manufacture of measuring instruments it is desirable to have casings which have different depths so that more or less apparatus may be placed in the casing as the need arises. Ordinarily this is not possible since instrument casings are made of castings and therefore they cannot be altered in size without a great deal of trouble and expense. It is an object of the present invention to overcome the objection of having a casing which must always be the same size.

It is anobject of the present invention to provide an instrument casing which is light in weight, but which has strength enough to rigidly support all of the mechanism that is placed in the casing. It is a further object of the invention to provide an instrument casing which may be easily changed in size by merely substituting one casing member for another, each of which may be attached to the same frame. It is a further object of the present invention to provide an instrument casing which is dust proof and fume proof so that the delicate measuring mechanism which is enclosed in the casing will not be affected by dirt or any fumes that may be in the surrounding atmosphere. It is afurther object of the invention to provide an instrument casing which is inexpensive to manufacture and which is readily adapted for use with all typesof measuring instruments.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its` advantages and specific objects obtained with its use, reference shouldbe had to the accompanying drawing and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

. f the drawing- Fig. 1 is a front view o'f the instrument casing with'a portion of the door broken away,

Fig. 2 is a view of the casing taken on line 2-2 of Fig. 1,

Fig. 3 is a view of a portion of Fig. enlarged scale.

Fig. 4 is a view taken online l-l of Fig. 1,

Fig. 5 is a view taken on lines 5-l-5 of Fig. 1,

2 on an (Cl. i3-151) Y Fig. 6 is a view of a modified form of theinvention. and

Fig. 7 is a view of another form of the invention.

5 Referring first to Fig. 1. there is shown a partl I forming the frame -of the casing which is, in this case. rectangular in shape and of a size equal to the desired height and width of the measuring instrument. The frame may either be a casting or may be made up from a series of structural members welded together to form a single part. This frame is formed with an inwardly extending flange 2 provided with reinforcements 3 in the form of ribs extending between the' frame I and the flange 2. The frame is also provided with an outwardly extending Vflange 4 that has a fiat front face 5. Projecting forwardly from the upper and lower portions of the ange l 'are shoulders 6 that receive hinge pins 'l for a d oor I, the details of which will be described below. The frame I with its flanges forms a light and very rigid support that is capable of supporting all of the instrument mechanism that is to be placed within the casing.

25 Since all of themechanism is supported on the frame I. there are provided along each side projctions 9 upon which the mechanism to be inserted in the casing is mounted. Each of these projections has`in it ashole I0 through which 30 pins may be inserted to hold the mechanism in place and to serve as hinge pins ifthe mechanism is to be swung in andout of the casing, asis quite often the case.

'Adapted to be attached to the frame I` and to` form the back and side walls of the casing is a sheet metal casing member Il which may be made so that the casing has any desired depth. The casing member I l may be made'in one piece if desired, but is preferably made of several pieces 40 bent and fastened together. For example, the top, back and bottom could be one piece of metal and the sides separate pieces fastened thereto. This construction forms a strong and inexpensive casing member. This member II has an outwardly extending flange I2 around its front edge which is adapted to be received in a recess I3 formed in the back of the ange I. The frame I is formed with a slightly tapered supporting surface as at I4 in order that the casing member I I may be easily slipped into place and the flange i2 will be properly aligned with the recess I3. A gasket member I5 made of some material such as rubber, is placed in the recess I3 between the nanges 4 and I2.so that a dust proof joint will 55 be formed between these two anges. Fastened to the interior of the casing II is a series of angle membersA It that are adapted to threadedly receive screws I'I which freely extend through openings I8 in the flange 2. These angle members I6 may be made longer than shown, if desired, so that they, in eiect, form a reinforcement around the edges of member II.

In assembling the parts I and II of the instrument casing the gasket I is rst placed in the recess I3 and the member II is then placed over the flange I. After this screws I1 are inserted in place and tightened. 'I'his draws parts Il` and II closely together so that the casing is in eiect a single piece. It is noted that the only exterior joint appears between anges 4 and I2 and if the instrument casing is ush mounted, as is usually the case, this joint will not be visible. The casing, therefore, to all intents and purposes will be a single piece.

The door 8 is provided around its inner edge with a gasket I9 made of rubber or similar material so that when the door is closed a dust and fume proof joint will also be formed between the door and the casing. It is noted that the anges 6 extend to the to'p and bottom edges of the door so that dust which might settle on the upper surfaces will notfall in the casing when the door is open. The door l is provided with a window that is held in place by spring clips y 2l which are attached by screws 22 to the inner invention which differs from that previously described only in the manner inwhich the casing, member II is attached to the frame I. In this embodiment of the invention a groove 24 is formed around the edge of the frame between the horizontal supporting surface I4 and the iiange 4. 'I'his groove is filled with some suitable tween them, although one may obviously be used Y .if desired.

statutes, I have illustrated and described the best Iform of my invention now 'known to me, it will be apparent to those skilled in the art that changes may be made in the form of -the appa ratus disclosed without departing from the spirit of my invention as set forth in the appended claims, and that in some cases certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

Having now described this invention, what I claim as new and desire to secure by Letters Patent is:

1. An instrument casing comprising a rigid supporting frame the shape of the casing, said frame having an outwardly extending flange around it, a formed sheet metal member forming the walls of the casing and having an outwardly extending iiange at its edge, said member adapted to v with a supporting surface, one end of the sur-v face terminating in an outwardly extending flange that has a recess in it on the side toward calking compound 25 or gasket so thatwhen 45 the Supporting surface, a member fOrming the the member II is pulled up against the flange 4 a tight joint will be formed between the two.

-In this embodiment the ange 4 is provided with an opening through which a screw 28 is passed.

side walls and the back of said casing provided around one edge with an outturned flange, said frame and member being of such a size that the member is received by the supporting surface of.

This screw is threaded into an opening in the the frame withthe ilange on the member reange I2 and serves to draw the flanges 4 and I2 tightly together. In this construction, as in `the construction previously described. there is no joint visible between the two parts except that ceived by the recess of the ange on the frame, mans to seal the joint between the two, and means y to rigidly hold the frame and member together.

3. An instrument casing having a hollow frame betweenthe flanges 4 and I2 and this jointcan- 55 the shape of the casing, said trame being pronot be seen if the instrument is flush mounted and is not conspicuous in any case.

A further embodiment of the invention is disclosed in Figure 7. As shown in this figure the frame 28 corresponds to the frame I of the m proceeding figures except that it does not have the inwardly extending ange 2. In this embodiment the frame 2l is placed over the casing member Il instead o'f in it as in the other emvided with inwardly and with outwardly projecting flanges extending around the same, a memy ber forming the side walls of the casing, a ange line similar to that of the casing and forming the front opening of the same, said frame having an outwardly extending vilange formed thereon, a box-like sheet metal member forming the back and side walls of the casing and being open at the front, an outwardly extending ange around the edge of the open front of said member, said are welded together no gasket is necessary beframe being of such a size that it will telescopically receive said member with the upstanding flanges abutting each other, and means joining 'said flanges together to hold said frame and member in their assembled relation.

5. An instrument casing comprising in com bination a rigid frame with an outstanding flange extending around .the same, a pair of horizontal parallel ledges extending forwardly from opposite sides of said flange, a box-like member forming the back and sides of said casing and being open at the front, an outwardly extending flange around the edge of said opening, said frame and member being of such size that said member may be received in said frame with said fianges abutting, the ange on said member being in front of the flange on said frame,- means to hold said flanges together, and a door. for said casing hinged tothe ledges on said frame whereby when the door is closed it will engage the flange on said member.

6. Inan instrument casing the combination of a rigid rectangular frame member adapted to form the open front of the casing, said frame being formed with a at front face, a pair of parallel ledges extending from opposite sides of said front face, a box-like member being open at the front forming the sides and back of the casing, said member having an outwardly extending flange around its open front, said frame and member being of such size that said frame can receive said member with the flange of said member lying against the front face of said frame. means to hold said face in assembled relation with the flange on said member extending in front of said face, a door for said casing iitted between said ledges and having a face adapted to engage the front of the flange on said member, a gasket attached to the face of said door to cooperate with said flange and means to hinge said door to said ledges.

'7. In an instrument casing the combination of a rigid rectangular frame member adapted to form the open front of the casing, said frame being formed with a fiat face, a pair of parallel ledges extending from opposite sides of said frame, a box-like member being open at the front forming the sides and back of the casing, said member having an out-wardly extending flange JOHN A. CALDWELL. 

